It is known that error correction processing is performed for each of the plurality of areas with a predetermined frequency to correct an error of a setting value that is stored in a plurality of areas of a memory. Further, a technique is known to divide a memory into a plurality of memory areas and to set a frequency with which error correction processing of each setting value that is stored in a plurality of memory areas in accordance with a degree of importance of the stored setting value (for example, see Patent Documents 1 and 2). In the conventional technique, the frequency performing error correction processing is set at the time of shipment of a product.